Heat exchange apparatus



Jan. 14, 1958 R. M. STEPHANI HEAT EXCHANGE APPARATUS Filed Oct INVENTORRICHARD M.STEPHANI ATTORNEY HEAT EXCHANGE APPARATUS Richard M. Stephani,Crum Lynne, Pa., assignor to Westinghouse Electric Corporation, EastPittsburgh, Pa., a corporation of Pennsylvania Application October 1,1953, Serial No. 383,550

4 Claims. (Cl. 257-239) This invention relates to heat exchangers, moreparticularly to an arrangement in which a plurality of heat exchangersare included in a common shell, and it has for an object the provisionof improved apparatus of this character.

in present day power plant design, it is often desirable to arrange aplurality of feedwater heaters having U- shaped tube bundles ofdifierent lengths in a common shell in order to save space and to reduceexpense in manufacture. It has been proposed to arrange a plurality ofsuch feedwater heaters in a common shell in such a manner that the waterboxes are all disposed at one end of the shell. Since the tube lengthsof the feedwater heaters are not the same, this arrangement results inconsiderable wasted space for the shell must necessarily belong enoughto accommodate the longest heater. Also, the diameter of the shellassumes large proportions in order to accommodate the tube bundles ofall the feedwater heaters. It is desirable to obviate a shell of largediameter for economic reasons, since a large diameter shell is morecostly to manufacture. Also, it is desirable to maintain the diameter ofthe shell at a minimum, since a heat exchanger structure of this type isoften installed in the inlet neck of a condenser for a steam turbine.The steam flow area in the neck of the condenser is critical andexcessive restriction of the of the flow area by a large diameter heatexchanger shell is highly undesirable.

In view of the above, it is a further object of the invention to providea structure having disposed therein a plurality of heat exchangersutilizing tube bundles of different lengths and arranged to reduceunnecessary space to a minimum.

A more specific object is to provide a structure having three heatexchangers of the above type disposed therein in a simple and compactarrangement, each of said heat exchangers having a steam inlet and acondensate discharge outlet and one of said heat exchangers having atube length approximately equal to the sum of the tube lengths of theremaining heat exchangers.

A still further object is to provide elongated tubular shell having along tube bundle and water boxes may be readily demounted for servicing.

In accordance with the invention, there is provided an elongated tubularshell having a long tube bundle and a somewhat shorter tube bundleextending into the shell from one end, the tube bundles being supportedby a common tube plate and having a unitary water box. A third tubebundle having a length approximately equal to the difierence in lengthof the two first-mentioned tube bundles, extends into the shell from atube plate and water box structure disposed at the opposite end andtakes up the space beyond the second-mentioned above tube bundle. Theshell is divided into three vapor-tight compartments, one for each tubebundle, and is provided with steam inlet and condensate outletconnections for each of the compartments.

heat exchange ap- St tes Patent The above and other objects are efiectedby the invention as will be apparent from the following descriptiontaken in connection with the accompanying drawings, forming a part ofthis application, in which:

Fig. 1 is a vertical longitudinal sectional view of a structureembodying the invention;

Fig. 2 is a cross-sectional view taken on line 11-11 of Fig. 1; and

Fig. 3 is a longitudinal elevational view of the structure shown in Fig.1, with parts thereof partially exploded or demounted.

In the drawing, there is shown heat exchange apparatus comprising atubular shell 10 having a substantially centrally disposed longitudinalpartition 11 and a transverse partition 12 connected to a substantiallymedian portion of the longitudinal partition 11 and extending therefromto the wall of the shell, thereby dividing the shell into three separatecompartments a, b and c. It will be noted that the compartment a extendsfrom one end of the shell to the other and is the largest, while thecompartments b and c extend from the transverse partition 12 in oppositedirections to the ends of the shell and are substantially half the sizeof the compartment a.

A plurality of U-shaped tube bundles 13, 14 and 15 are disposed withinthe shell. The tube bundle 13 is the longest and is disposedlongitudinally in compartment :1. The tube bundles 13 and 14 aresupported in side-by-side relation by a tube plate 16, while the tubebundle 15 is supported by a tube plate 17. The tube plates 16 and 17overlie the openings in the opposite ends of the shell 10 and serve toassist in isolating the compartments a, b and c from each other.

Each of the compartments a, b and c is provided with separate steaminlet connections 18, 19 and 20, respectively, connectible to anysuitable steam supply (not shown) and discharge outlet connections 21,22 and 23, respectively, connectible to any suitable water utilizing orstorage device (not shown).

A water box structure 25 having a water inlet connection 26 and a wateroutlet connection 27 is mounted on the tube plate 16 and is providedwith partitions 25a:

and 25b for directing the flow of water through the U-shaped tubebundles 13 and 14 in a series How arrangement. A second water box 28having a water inlet connection 29 and a water outlet connection 30 ismounted to the tube plate 17 and is provided with a horizontal partition28a which directs flow of water through the tube bundle 15.

The water outlet connection 27 of the water box 25 is preferablyconnected to the water inlet connection 29 of the water box 28 by aconduit indicated by the dotand-dash arrows 31, so that the water whichflows into the box 25 through the inlet connection 26 flows through 14and 15 in a series circuit followthe tube bundles 13, ing the path shownby the arrows 32 and is then discharged through the water outletconnection 30 at a higher temperature than when it is admitted throughthe inlet 26.

The tube bundle 13 may be provided with the usual transverse bafiies 33aand 33b to provide a tortuous path for the steam flowing through thecompartment a and across the surfaces of the tubes contained therein, aswell understood in the art. Similarly, the tube bundles 14 and 15 may beprovided with transverse baflles 34a and 3412.

Although the water boxes 25 and 28 have been shown bolts 39 and clampthe tube plates 16 and 17 therebetween to close the ends of the shellagainst leakage of steam to the atmosphere. When in the above clampedrelation, the tube plates 16 and 17 abut the ends of the longitudinalbaffle 11 to prevent flow of steam between compartment at andcompartments b and c. p

The tube bundles 13, 14 and 15 may be arranged in their compartments, a,b and c, respectively, in such a manner that steam entering by theinlets may expand before contacting the surfaces of the tubes. Forexample, as shown in Figs. 1 and 2, the tube bundle 13 is disposed inthe lower portion of the compartment a, while the upper portion of thecompartment contains no tubes and forms a steam expansion space.Similarly, as best shown in Fig. 2, the tube bundle 15 is disposed inthe compartment c in such a manner that the proportion of thecompartment adjacent theinlet connection 20 is devoid of tubes.

When it is desired to demount the water boxes 25 and 28 and the tubebundles 13, 1 and 15 for servicing, the conduit 31 may be disconnectedand the bolts 39 may be removed whereby, as indicated in Fig. 3, afterthe water box is removed, the tube bundles 13 and 14 may be withdrawnfrom the shell to the right as viewed in Fig. 1, together with theirtube plate 16 as a unit. Similarly, after the water box 28 is removed,the tube bundle may be withdrawn from the shell to the left togetherwith its tube plate 17 as a unit.

It will be noted that the tube bundle 13 is approximately of a lengthequal to the sum of the lengths of tube bundles 14 and 15 and that itextends substantially from one end of the shell 10 to the other, whilethe tube bundles 14 and 15 extend from the opposite ends of the shellinwardly towards each other and terminate adjacent the transversepartition 12. Thus, the space within the shell is utilized to thefullest, while the compartments a, b and 0 together with their tubebundles 13, 14 and 15, respectively, retain their separate identity andmay be heated by steam at different temperatures and pressures.

Also, with the above arrangement, the heat exchange may be effected in ahighly efiicient manner and linear expansion of the tube bundles is freeto occur without stressing of adjacent parts.

By utilizing steam in the compartments a, b and c, at successivelyhigher temperatures and pressures, the water may be heated in steps,that is, the incoming water passing through tube bundle 13 is heated toone tempera ture, is then heated to a higher temperature while passingthrough tube bundle 14 and is finally heated to its highest temperaturewhile passing through tube bundle 15.

While the invention has been shown in but one form, it will be obviousto those skilled in the art that it is not so limited, but issusceptible of various changes and modifications without departing fromthe spirit thereof.

What is claimed is:

l. A heat exchanger comprising a tubular shell having openings atopposite ends, a longitudinal imperforate partition mounted in saidshell and extending to said opposite ends, a transverse imperforatepartition extending from said longitudinal partition to said shell, saidpartitions dividing said shell into a large substantially fluid-tightcompartment and a pair of substantially smaller substantiallyfluid-tight compartments, said smaller compartments being disposed inend-to-end relation and being accessible from the opposite ends of saidshell, a bundle of U-shaped tubes disposed in each of said compartments,a first water box structure including a first tube plate associated withthe tube bundle in said large compartment and one of the tube bundles insaid smaller compartments and providing for circulation of watertherethrough in a plurality of passes, a second water box structureincluding a second tube plate associated with the other of the tubebundles in said smaller compartments and providing for circulation ofWater therethrough in a plurality of passes, said tube plates beingdemountably attached to said opposite ends of the shell and closing saidopenings, said shell having a steam inlet and a discharge outlet foreach of said compartments, each of said tube plates being individuallydemountable from said shell together with its associated tube bundle orbundles as a unit.

2. A heat exchanger comprising a tubular shell having openings atopposite ends, a longitudinal imperforate partition mounted in saidshell and extending to said opposite ends, a transverse imperforatepartition extending from said longitudinal partition to said shell, saidpartitions dividing said shell into a large substantially fluid-tightcompartment and a pair of substantially smaller substantiallyfluid-tight compartments, said smaller compartments being disposed inend-to-end relation and being accessible from the opposite ends of saidshell, a bundle of U-shaped tubes disposed in each of said compartments,a first water box structure including a first tube plate associated withthe tube bundle in said large compartment and one of the tube bundles insaid smaller compartments and providing for circulation of watertherethrough in a plurality of passes, a second water box structureincluding a second tube plate associated with the other of the tubebundles in said smaller compartments and providing for circulation ofwater therethrough in a plurality of passes, said tube plates beingdemountably attached to said opposite ends of the shell and closing saidopenings, said shell having a steam inlet and a discharge outlet foreach of said compartments, each of said tube plates being individuallydemountable from said shell together with its associated tube bundle orbundles as a unit, the tube bundle in said large compartment having alongitudinal dimension substantially equaling the sum of thelongitudinal dimensions of the tube bundles in said pair of smallercompartments.

3. A heat exchanger comprising a tubular shell having openings atopposite ends, a longitudinal imperforate partition mounted in saidshell and extending to said opposite ends, a transvesre imperforatepartition extending from said longitudinal partition to said shell, saidpartitions dividing said shell into a large substantially fluidtightcompartment and a pair of substantially smaller substantiallyfluid-tight compartments, said smaller compartments being disposed inend-to-end relation and being accessible from the opposite ends of saidshell, a bundle of U-shaped tubes disposed in each of said compartments,a first water box structure including a first tube plate associated withthe tube bundle in said large compartment and one of the tube bundles insaid smaller compartments and providing for circulation of watertherethrough in a plurality of passes, a second water box structureincluding a second tube plate associated with the other of the tubebundles in said smaller compartments and providing for circulation ofwater therethrough in a plurality of passes, said tube plates beingdemountably attached to said oppositeends of the shell and closing saidopenings, said shell having a steam inlet and a dicharge outlet for eachof said compartments, each of said tube plates being individuallydemountable from said shell together with its associated tube bundle orbundles as a unit, the tube bundle in said large compartment having alongitudinal dimension substantially equaling the sum of thelongitudinal dimensions of the tube bundles in said pair of smallercompartments, and a conduit disposed externally of said shell andcommunicating with said water boxes, said conduit providing for flow ofWater from one to the other of said water boxes.

4. A heat exchanger comprising a tubular shell having first and secondopenings at opposite ends, a longitudinal imperforate partition disposedin said shell and extending to said opposite ends, a substantiallytransversely disposed imperforate partition extending from asubstantially median portion of said longitudinal partition to saidshell, said partitions dividing said shell into a large compartment andfirst and second substantially smaller compartments, said smallercompartments being disposed in endto-end relation with each other, saidfirst compartment being accessible from said first opening and saidsecond compartment being accessible from said second opening, each ofsaid compartments having a bundle of U-shaped tubes disposed therein, afirst Water box structure including a first tube plate demountablyattached to said shell and closing said first opening, the tube bundlesdisposed in said large compartment and said first compartment beingsupported by said first tube plate and having fluid communication withsaid first Water box, a second water box structure including a secondtube plate demountably attached to said shell and closing said secondopening, the tube bundle in said second compartment being supported bysaid second tube plate and having fluid communication with said secondwater box, each of said compart- 15 References Cited in the file of thispatent UNITED STATES PATENTS 686,313 Mann NOV. 12, 1901 1,251,262Maurice Dec. 25, 1917 2,049,748 Rathbun Aug. 4, 1936 2,360,408 Dunn eta1 Oct. 17, 1944 2,361,726 Weimar Oct. 31, 19

